Here is some Black Flourite Sand in my 10 gallon tank:


This tank has been set up for about 6 weeks now, as a non-CO2 tank. The plants are all alive, very slowly growing. It has a sub layer of Diamond Black (leonardite). Most of the Flourite was just poured in dry, no washing, but the very top layer is washed briefly. No cloudiness when I filled the tank, other than a slight haze, which cleared up by the next day. Flourite sand is indeed very fine grained, with much of it less than 1 mm in grain size.